1. Field
The present disclosure relates generally to aircraft and, in particular, to managing information in aircraft. Still more particularly, the present disclosure relates to a method and apparatus for obtaining information from line replaceable units in an aircraft.
2. Background
Aircraft increasingly have more and more electrical systems that control the operation of the aircraft, monitor the operation of the aircraft, and provide other functions. These electrical systems may be nodes in an aircraft network data processing system. Oftentimes, these nodes are implemented as line replaceable units. A line replaceable unit receives information needed to perform operations through connections to various devices.
For example, a line replaceable unit in an environmental control system may have connections to temperature sensors, airflow sensors, carbon dioxide sensors, vent actuators, cooling units, heating units, and other devices. The line replaceable unit may receive information from the different sensors and control operation of the heating units, cooling units, and vents to provide a desired environment within the aircraft. These different components are typically connected directly to the line replaceable unit. These connections may be made using wires and data buses that are directly connected to a line replaceable unit.
Currently, if another line replaceable unit needs temperature information from the same locations as the sensors for the first line replaceable unit, additional sensors may be placed at those locations and connected to the second line replaceable unit, or additional connections may be made between the second line replaceable unit and the existing temperature sensors. The addition of new sensors or new connections from additional sensors may require the routing of wiring through the aircraft. In existing aircraft, the ability to route new wiring may be limited and more costly than desired.
Adding additional sensors may increase the cost and weight of the aircraft more than desired. Connecting the second line replaceable unit to the temperature sensors using wires or optical fibers may also increase the time and expense needed. Further, generating additional communications links to the different sensors or components may take more time than desired and increase the complexity of the aircraft more than desired. Moreover, this increase in wires or optical fibers within the aircraft also may result in more maintenance than desired.
Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.